The congenital defect of tetralogy of Fallot (ToF) is based on four anatomical defects of the heart, affecting the structure and function of the heart. Consequently, there is oxygen-poor outflow of blood from the heart, with cyanotic spells, especially with crying. This condition is diagnosed by Best Cardiologist in Karachi in early infancy, and treated according to severity.
Read on to know more about TOF:
What is tetralogy of Fallot?
Tetralogy of Fallot is a combination of four heart defects, including:
- Ventricular septal defect (VSD): the septum of the heart separating the right and left ventricles or the lower chambers, has a hole, thereby allowing the oxygenated blood from the lungs in the left heart, to mix with the deoxygenated blood in the right heart to mix.
- Overriding of the aorta: in tetralogy of Fallot, the aorta straddles or overrides both the right and left ventricle instead of coming out of the left ventricle alone.
- Right ventricle hypertrophy: there is increased thickness of the wall of the right ventricle, making it difficult to fill and pump.
- Pulmonary artery stenosis: this is the narrowing of the vessel leading from the right ventricle to the lungs.
The combination of these heart defects in tetralogy of Fallot reduce the blood flow to the body and enhance oxygen deprivation in the tissues.
What are the signs and symptoms of tetralogy of Fallot?
The main signs and symptoms of tetralogy of Fallot are:
- Bluing of skin, nail beds and lips—due to oxygen deprivation
- Tet spells when crying
- Loss of consciousness
- Difficulty in breathing especially during exercise or feeding
- Easily tiring out
- Prolonged crying in babies
- Clubbing of finger and toe nails
- Fussy baby
- Heart murmur
- Difficulty in feeding the baby
How is tetralogy of Fallot diagnosed?
In many cases, babies are diagnosed with tetralogy of Fallot before birth through prenatal ultrasounds. After birth, thorough history and physical examination of the baby, as well as, diagnostic investigations help to make diagnosis. These investigations include:
- Pulse oximetry—to check the oxygen levels in the blood
- Chest x-ray
- Cardiac CT/MRI
- Electrocardiogram (ECG)
- Cardiac catheterization
- Exercise stress testing
What are the treatment options for tetralogy of Fallot?
The treatment of tetralogy of Fallot is mostly surgical repair. These surgeries are performed when the baby is at least six months old.
Temporary shunt operation
If surgical repair is not possible for the baby, a temporary shunt operation is done; this involves shunt placement between the pulmonary artery and the aorta which helps with blood flow into the lungs. Later, when the baby is old enough, this procedure is reversed and full repair surgery is performed.
Full surgical repair
Complete surgical repair involves correction of:
- ventricular septal defect
- widening of the pulmonary valve
- removal of the excess thickened tissue of right ventricle
What are the risk factors of tetralogy of Fallot?
The exact cause for tetralogy of Fallot is not understood yet, however, the following risk factors are associated with the disease etiology:
- Drinking during pregnancy
- Viral illness during pregnancy especially rubella virus that causes German measles
- Poor nutrition during pregnancy
- Baby diagnosed with Down syndrome or DiGeorge syndrome
- Mother’s age older than 40 years
- Tetralogy of Fallot in the parent of the baby
What are the complications of tetralogy of Fallot correction surgery?
The correction of tetralogy of Fallot requires open-heart surgery. Even though, most surgeries have a good prognosis, certain complications can arise, which include:
- Leakage of the tricuspid valve
- Leakage of the pulmonary valve
- Enlargement of the right ventricle
- Enlargement of the left ventricle
- Irregular heartbeats or arrhythmias
- Coronary artery disease
- Ventricular septal defect
- Dilation or enlargement of the ascending aorta (aortic dilation)
- Sudden cardiac death
For individuals suffering from congenital heart diseases including tetralogy of Fallot, regular checkups with Cardiologist in Islamabad are mandated, as these individuals need lifelong care and monitoring for complications.